title: jason p. lake chichester, college lane, chichester
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Journal of Strength and Conditioning Research Publish Ahead of PrintDOI: 10.1519/JSC.0000000000000538
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Title: Magnitude and relative distribution of kettlebell snatch force-
time characteristics
Running Title: Kettlebell Snatch Mechanics
Authors: Jason P. Lake1, Brandon S. Hetzler2, and Mike A. Lauder1.
Research Address: 1Department of Sport and Exercise Sciences, University of
Chichester, College Lane, Chichester, United Kingdom
2Department of Sports Medicine and Athletic Training, Missouri
State University, Springfield, Missouri, United States of
America
Correspondence: Jason P. Lake, Department of Sport and Exercise Sciences,
University of Chichester, College Lane, Chichester, United
Kingdom, PO19 6PE. Tel: +44 1243 816 294, Fax: +44 1243
816080, email: J.Lake@chi.ac.uk
Abstract
The aim of this study was to compare mechanical output from kettlebell snatch and 2-
handed kettlebell swing exercise. Twenty-two men performed 3 sets of 8 kettlebell snatch
and 2-handed swing exercise with a 24 kg kettlebell on a force platform. Vertical and
horizontal net impulse, mean force, displacement, the magnitude and rate of work
performed displacing the kettlebell-and-lifter center of mass (CM), phase durations and
impulse ratio (horizontal to resultant) were calculated from force data. The results of
repeated measures analysis of variance showed that: 1) vertical CM displacement was
significantly larger during kettlebell snatch exercise (22±4 vs. 18±5 cm, p=0.001), and
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vertical CM displacement was significantly larger than horizontal CM displacement,
regardless of exercise (20±3 vs. 7±1 cm, p<0.0001); 2) the magnitude (253±73 vs. 3±1 J,
p<0.0001) and rate of work (714±288 vs. 11±4 W, p<0.0001) performed to vertically
displace the CM was larger than the horizontal equivalent in both exercises, and the
magnitude (5±2 vs. 1±1 J, p<0.0001) and rate of work (18±7 vs. 4±3 W, p<0.0001)
performed to horizontally displace the CM during 2-handed swing exercise was
significantly larger than the kettlebell snatch equivalent; 3) this was underpinned by the
magnitude of horizontal impulse (29±7 vs. 18±7 N.s, p<0.0001) and the impulse ratio (23
vs. 14%, p<0.0001). These findings reveal that, apart from the greater emphasis 2-handed
swing exercise places on horizontal mechanical output, the mechanical output of the two
exercises is similar. Research shows that 2-handed swing exercise improves maximum
and explosive strength. These results suggest that strength and conditioning coaches
should consider using kettlebell snatch and 2-handed swing exercise interchangeably for
the ballistic component of athlete strength and conditioning programs.
Keywords: impulse; power; Hardstyle; asymmetry; resistance exercise
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Kettlebell snatch mechanics
1
INTRODUCTION
Interest in the relative benefits of including kettlebell exercises, like the 2-handed swing, in
athlete and general population training programs has recently increased (2, 9, 10, 11, 12, 13,
15, 18). Research has demonstrated similarities between mechanical output from 2-handed
swing exercise, which is illustrated in Figure 1, and back squat and jump squat exercise (10).
Specifically, the largest impulse applied to the combined kettlebell-and-lifter center of mass
(CM) of 276.1 (±45.3) N.s was recorded during 2-handed swing exercise with 32 kg. This
was 34% larger than the largest back squat impulse, and 16% larger than the largest jump
squat impulse. Furthermore, there were no significant differences between the highest 2-
handed swing exercise (3281 ± 970 W) and jump squat (3468 ± 678 W) peak power. This
suggests that 2-handed swing exercise could provide a training stimulus sufficient to improve
the ability to apply large amounts of force in short periods of time (impulse) and large
amounts of force to a moving a mass of interest quickly (power).
***Insert Figure 1 about here***
Subsequent work by investigators showed that—with relatively light loads (12 to 16 kg)—2-
handed swing exercise provided a training stimulus that was sufficient to provide a strength
and power training effect (11). Recreational male athletes with limited resistance training
experience performed 12 minutes of 30 s 2-handed swing exercise alternated with 30 s
recovery twice a week for 6 weeks. Vertical jump performance improved by 13% (20 ± 0.05
cm to 23 ± 0.05 cm), while maximum strength improved by 10% (half squat = 156 ± 22 kg to
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Kettlebell snatch mechanics
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174 ± 22 kg), demonstrating the potential of 2-hand swing exercise to provide an effective
and relatively time efficient strength and power training protocol. While these investigators
(11) did not suggest that kettlebell exercise should, or indeed could, replace traditional
resistance exercise, they did suggest that it could be used to provide variety to athlete strength
and conditioning programs.
Although 2-handed swing exercise has received research attention, the potential for other
popular kettlebell exercises, like the kettlebell snatch, to provide a strength and power
training effect have not been studied. The kettlebell snatch is a unilateral exercise that is
illustrated in Figure 2, and has been described in detail (17). It begins with the lifter
performing a 1-handed swing but concludes with the lifter catching the kettlebell overhead on
a locked arm. The aim of 2-handed swing exercise is to project the kettlebell forward, which
creates an arc-like trajectory. During kettlebell snatch exercise flexing the elbow joint
controls this arc-like trajectory, and greater emphasis is given to vertical displacement of the
kettlebell so that it can be caught overhead before the sequence is reversed and repeated.
***Insert Figure 2 about here***
Proponents of kettlebell snatch exercise suggest that it has the potential to improve what is
often referred to as explosive strength. The same load is often used in the 2-handed kettlebell
swing and kettlebell snatch assessment portions of popular kettlebell certifications, like the
Russian Kettlebell Certification (RKC), with healthy men typically using 24 kg. Therefore,
during kettlebell snatch exercise the same load is displaced further with one hand, suggesting
that a larger mechanical output is required compared to 2-handed swing exercise. However,
the mechanical output from kettlebell snatch exercise has not been established and this
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Kettlebell snatch mechanics
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represents a gap in the literature. Addressing this gap by studying force-time curves recorded
from kettlebell snatch exercise could, therefore, provide data that will enable strength and
conditioning coaches to make informed decisions about the relative merit of including
kettlebell snatch exercise in athlete strength and conditioning programs. Therefore, the aims
of the current study were to: 1) establish mechanical output from kettlebell snatch exercise;
2) quantify the relative distribution of mechanical output; and 3) compare these data to
equivalent data from 2-handed swing exercise. It was hypothesised that greater emphasis
would be placed on vertical net impulse to perform more mechanical work to vertically
displace the CM further during kettlebell snatch exercise. It was also hypothesized that
greater emphasis would be placed on horizontal net impulse to perform more mechanical
work to horizontally displace the CM further during 2-handed swing exercise.
METHODS
Experimental approach to the problem
To address the aims of this study a within-subjects repeated measures design was used.
Braking and propulsion phase vertical and horizontal ground reaction forces (GRF) were
recorded from 22 kettlebell-trained men performing sets of kettlebell snatch and 2-handed
swing exercise with a 24 kg kettlebell on a force platform. Dependent variables of vertical
and horizontal net impulse, mean force, displacement of the CM, the magnitude and rate of
work performed displacing the CM, phase durations, and impulse ratio (the ratio of horizontal
to resultant impulse) were obtained from vertical and horizontal forces recorded from a
portable force platform, and analysed using repeated measures analysis of variance and
paired sample t tests.
Subjects
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Kettlebell snatch mechanics
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Twenty-two men between the ages of 28 and 41 years (mass: 75.2 ± 14.6 kg; stature: 174 ±
13.5 cm), and with a minimum of 1 year’s kettlebell snatch exercise and 2-handed swing
exercise experience volunteered to participate. Subjects had been free from lower-body
pathology for at least 6 months before data collection. Ethical approval for this study was
gained from the institutions ethical review panel. After a thorough explanation of the study
aims, protocols, and potential risks, subjects provided written informed consent.
Procedures
Subjects attended a single laboratory based testing session, during which they performed a
self-selected warm up followed by three sets of 8 maximum effort kettlebell snatches and 2-
handed swings with a 24 kg kettlebell (Dragon Door Kettlebells, Torrance, CA, USA).
Exercises were performed in accordance with the technique described by Tsatsouline (17),
exercise order was counterbalanced, and subjects rested for three minutes between each set.
Subjects attended the laboratory approximately 2 hours post-prandial, having been instructed
to avoid heavy resistance exercise for at least 48 hours before testing. Subjects were
instructed to perform kettlebell snatch exercise and 2-handed swing exercise with the
intention of moving the kettlebell as quickly as possible (using correct technique), and were
given verbal encouragement throughout data collection.
Instrumentation
All kettlebell snatch and 2-handed swing exercise were performed on a 101.6 by 76.2 cm
portable force platform (AccuPower, AMTI, Watertown, MA, USA) that recorded GRF at
1000 Hz using NetForce software (AMTI, Watertown, MA, USA). All kettlebell snatch
exercise began with subjects standing still on the force platform with the kettlebell held at
arm’s length overhead, and did not begin until the word of command: “go” was given.
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Kettlebell snatch mechanics
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Conversely, 2-handed swing exercise began with subjects standing still on the force platform
with the kettlebell held in both hands at arm’s length in the ‘finished deadlift’ position, with
the kettlebell lightly touching the upper-thighs, and did not begin until the word of command:
“go” was given. Subjects were instructed to adopt these positions and stand still for 3 seconds
before and after each set. This enabled the recording of a period of quiet standing GRF from
which combined kettlebell-and-lifter weight could be obtained. This also enabled removal of
drift from the GRF by obtaining the acceleration of the CM, calculating then removing its
mean, and repeating this process on the velocity-time curves, then repeating the process on
the displacement-time curves, both horizontal and vertical. Net force was obtained by
subtracting combined kettlebell-and-body weight from GRF, CM acceleration by dividing net
force by combined kettlebell-and-body mass, and CM velocity and displacement, both
horizontal and vertical, by integrating the respective acceleration-time and velocity-time
curves using the trapezoid rule (4). Work performed by displacing the CM, both vertically
and horizontally, was obtained by calculating the area under the respective force-
displacement curves, and these were divided by phase duration to yield the respective phase
mean power.
Data from the active braking and propulsion phases of both exercises were studied, and these
phases were determined from the vertical velocity-time curve. The beginning of the braking
phase was identified from the lowest velocity, and continued until velocity changed from
negative to positive. This marked the beginning of the propulsion phase, which continued
until peak vertical velocity was achieved. Vertical and horizontal impulse from the braking
and propulsion phase was calculated as the area under the respective phases of the vertical
and horizontal net force-time curves using the trapezoid rule (4). Displacement of the CM
during the braking and propulsion phase was calculated as the range of motion between the
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Kettlebell snatch mechanics
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lowest and highest position of the CM from the displacement-time curve during these
respective phases. Finally, braking and phase durations were also calculated. The impulse
ratio parameter was adapted from the force ratio parameter recently used to study force
application in sprint performance (14), and was calculated as the ratio of anterior-posterior
horizontal to resultant force.
All GRF data were processed in a customized LabVIEW program (National Instruments,
Version 10.0, Austin, Texas, USA), which enabled selection of data from the third, fourth
and fifth repetition of each set (which were then averaged for further analysis), and
identification of braking and propulsion phases. Within session test-retest reliability of the
methods used to obtain dependent variables was generally high (intraclass correlation
coefficients R values between 0.864 and 0.996).
Statistical Analyses
All data were presented as mean (SD). The dependent variables were vertical and horizontal
net impulse, vertical and horizontal displacement of the CM, the magnitude and rate (mean
power) of work performed by vertically and horizontally displacing the CM, in addition to
phase durations; exercise (kettlebell snatch and 2-handed swing exercise), plane (vertical and
horizontal [anterior and posterior]), and phase (braking and propulsion) were the independent
variables. Net impulse, work, and mean power, were investigated using a 3-way (exercise by
phase by plane) repeated measures analysis of variance. Displacement of the CM (exercise by
plane - propulsion phase only) and phase durations (exercise by phase) were investigated
using a 2-way repeated measures analysis of variance. Bonferonni corrected planned
comparisons were performed where appropriate. All statistical analyses were performed
using SPSS (version 17.0; SPSS Inc., Chicago, IL, USA), and an alpha level of p ≤ 0.05 used
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Kettlebell snatch mechanics
7
to indicate statistical significance. Effect sizes (ES) were quantified using the scale recently
presented by Hopkins et al. (2), where effect sizes of 0.20, 0.60, 1.20, 2.0, and 4.0
represented small, moderate, large, very large and extremely large, respectively.
***Insert Figures 3, 4 and 5 about here***
***Insert Tables 1 and 2 about here***
RESULTS
Representative force-time, velocity-time, and displacement-time graphs from kettlebell
snatch and 2-handed swing exercise are presented in Figures 3 to 8. Net impulse data are
presented in Table 1. Vertical net impulse was significantly larger than the horizontal
equivalent, regardless of exercise or phase (p < 0.0001, ES = 4.56). There were no significant
differences between kettlebell snatch and 2-handed swing exercise vertical impulse (p =
0.592, ES = 0.10), but 2-handed swing exercise horizontal impulse was significantly greater
than the kettlebell snatch equivalent (p < 0.0001, ES = 1.63). Phase significantly affected
impulse, but depended on exercise (p < 0.037). However, differences between propulsion
phase impulse and braking phase impulse during 2-handed swing exercise did not reach the
Bonferroni corrected alpha level of p ≤ 0.0004 (p = 0.015, ES = 0.20); there were no
significant differences between kettlebell snatch braking and propulsion phase impulse (p =
0.865, ES = 0.02).
***Insert Figures 6, 7 and 8 about here***
Mean (SD) braking and propulsion phase net mean force data are presented in Table 1.
Vertical mean net force was significantly larger than the horizontal equivalent, regardless of
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Kettlebell snatch mechanics
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exercise or phase (p < 0.0001, ES = 3.08). Horizontal 2-handed swing exercise mean net
force was significantly larger than the kettlebell snatch equivalent, regardless of phase (p <
0.0001, ES = 1.98). However, while differences between the vertical mean net force applied
during kettlebell snatch and 2-handed swing exercise approached statistical significance (p =
0.007 >Bonferonni corrected p = 0.004, ES = 0.71), differences between the horizontal
equivalent did not (p = 0.530, ES = 0.14). The only effect that phase had on mean net force
was that mean net vertical force applied during the braking phase of 2-handed swing exercise
was significantly greater than the propulsion phase equivalent (p = 0.001, ES = 0.36).
Phase duration data are presented in Table 3. There were no significant differences between
kettlebell snatch braking and propulsion phase duration (p = 0.863, ES = 0.05). However,
kettlebell snatch braking phase duration was significantly longer than the 2-handed swing
exercise equivalent (p < 0.0001, ES = 1.54). Furthermore, 2-handed swing exercise
propulsion phase duration was significantly longer than the braking phase equivalent (p <
0.0001, ES = 1.21). Displacement data are presented in Table 4. Vertical displacement of the
CM was significantly larger than horizontal displacement of the CM, regardless of exercise
and phase (p < 0.0001, ES = 6.16). Furthermore, vertical displacement of the CM during
kettlebell snatch exercise was significantly larger than during 2-handed swing exercise (p <
0.0001, ES = 1.20).
Work data are presented in Table 2. Work performed displacing the CM was significantly
affected by exercise, phase and plane (p = 0.004). Work performed vertically displacing the
CM was significantly greater than the horizontal equivalent, regardless of exercise and phase
(p < 0.0001, ES = 6.65). Work performed horizontally displacing the CM during 2-handed
swing exercise was significantly greater than the kettlebell snatch equivalent (p < 0.0001, ES
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Kettlebell snatch mechanics
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= 2.02). However, there were no significant differences between the amount of work
performed vertically displacing the CM during either kettlebell snatch or 2-handed swing
exercise (p = 0.186, ES = 0.23). A plane effect was found, but did not meet the Bonferonni
corrected alpha value of p = 0.004, and the ES were below 0.30.
Average power data are presented in Table 2. The power of displacing the CM was
significantly affected by exercise, phase and plane (p = 0.039). The power of vertically
displacing the CM was significantly greater than the horizontal equivalent, regardless of
exercise and phase (p < 0.0001, ES = 4.82). The power of horizontally displacing the CM
during 2-handed swing exercise was significantly greater than the kettlebell snatch
equivalent, regardless of phase (p < 0.0001, ES = 2.55). Finally, the power of vertically
displacing the CM during the braking phase of 2-handed swing exercise was significantly
greater than the propulsion phase equivalent (p < 0.001, ES = 0.28).
Impulse ratio data is presented in Table 5. Impulse ratio from 2-handed swing exercise was
significantly larger than the kettlebell snatch equivalent (p < 0.0001, ES = 2.15). However,
there was no significant difference between braking and propulsion phase impulse ratio,
regardless of exercise (p = 0.192, ES = 0.44).
***Insert Tables 3, 4 and 5 about here***
DISCUSSION
The aims of this study were to: 1) establish mechanical output from kettlebell snatch
exercise; 2) quantify the relative distribution of this mechanical output; and 3) compare these
data to equivalent data from 2-handed swing exercise. The main findings of this study show
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Kettlebell snatch mechanics
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that: 1) vertical CM displacement was significantly larger during kettlebell snatch exercise,
and vertical CM displacement was significantly larger than horizontal CM displacement,
regardless of exercise; 2) work performed and power achieved to vertically displace the CM
was larger than the horizontal equivalent in both exercises, and that work performed and
power achieved to horizontally displace the CM during 2-handed swing exercise was
significantly larger than the kettlebell snatch equivalent; 3) this was underpinned by the
magnitude of horizontal impulse and the impulse ratio.
Kettlebell snatch requires greater vertical mechanical output
It was hypothesized that a greater emphasis would be placed on vertical net impulse to
perform more mechanical work to vertically displace the CM further during kettlebell snatch
exercise. The results of the present study led to the rejection of this hypothesis. The CM was
vertically displaced 18% further (4 cm, ES = 0.98) during kettlebell snatch exercise.
However, there were no significant differences between vertical impulse or the work
performed and the power achieved to vertically displace the CM during kettlebell snatch
exercise. This appears to be a consequence of the aim of the kettlebell snatch exercise, which
is to vertically displace the kettlebell overhead. Significantly larger horizontal impulses were
applied during 2-handed swing exercise. This means that although similar vertical impulses
were applied during both exercises, the emphasis was on vertical displacement during
kettlebell snatch exercise, compared to the emphasis that was placed on horizontal
displacement during 2-handed swing exercise.
Kettlebell snatch exercise appears to rely on a more controlled application of force compared
to the more aggressive 2-handed swing exercise. This is supported by results from the present
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Kettlebell snatch mechanics
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study that show that 2-handed swing exercise braking phase impulse was within 4% of the
kettlebell snatch equivalent, and was applied 25% faster (ES = 1.54). This suggests that
bilateral nature of 2-handed swing exercise affords greater control over the kettlebell, which,
in turn, facilitates use of the stretch-shortening cycle (SSC).
Several reasons have been proposed to explain why use of the SSC in movements, like the
countermovement vertical jump, enhances performance during the concentric propulsion
phase, often significantly (1, 3, 4, 5). It appears that performance enhancement relies on a
combination of several factors that include increased active state, generation and use of
elastic energy, and that this improves the muscle length-tension relationship (1, 3, 4, 5). It
would appear that the net product of these mechanisms results in arrival at the braking-
propulsion phase transition immediately preceded by an eccentric braking phase that requires
the generation of vertical force that is sufficient to arrest continued negative displacement of
the CM, which, in turn is greater than the starting force of non-SSC movement (3, 4). This
could go some way to explain how six weeks of 2-handed swing exercise improved vertical
jump performance (11), and must be considered by strength and conditioning coaches when
they select exercises for athlete strength and conditioning programs.
2-handed swing exercise requires greater horizontal mechanical output
It was also hypothesized that greater emphasis would be placed on horizontal net impulse to
perform more mechanical work to horizontally displace the CM further during 2-handed
swing exercise. This hypothesis was also rejected. More horizontal impulse underpinned the
performance of more work at a greater power output to horizontally displace the CM.
However, horizontal displacement of the CM was not significantly greater during 2-handed
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Kettlebell snatch mechanics
12
swing exercise. In fact, it should be noted that horizontal CM displacement during kettlebell
snatch exercise was 25% larger and yielded a moderate to large effect size (2 cm, ES = 0.99).
This indicates that technique differences between kettlebell snatch and 2-handed swing
exercise do not extend to horizontal displacement of the CM. This finding was not expected,
but would appear to be underpinned by the rate of horizontal mechanical output during 2-
handed swing exercise. The greater control that the bilateral nature of 2-handed swing
exercise affords over the kettlebell was discussed above. However, the rate of horizontal
mechanical output enables the lifter to perform more work, and achieve higher power outputs
horizontally displacing the CM during 2-handed swing exercise. This may have important
implications for strength and conditioning coaches looking for plane-specific resistance
exercises. The 2-handed swing exercise appears to provide a greater horizontal mechanical
demand and could benefit athletes who need to apply relatively large horizontal impulses.
This is the first study to consider the mechanical output of kettlebell snatch exercise,
comparing it to 2-handed swing exercise to provide context. It is also the first to study the
direction in which vertical and horizontal impulse are applied during both braking and
propulsion phases of both exercises. In the present study, impulse ratio describes the ratio
between horizontal (anterior and posterior) and resultant impulse. This was based on a
method that was recently shown to be significantly related to sprint performance (14). Rather
than consider absolute magnitude, it considers technical efficiency, and, as such, could play
an important role in the identification of resistance exercises for athletes who need the ability
to apply relatively large horizontal impulses (16). The impulse ratio of 2-handed swing
exercise reported in the present study matched recently reported sprint performance impulse
ratio data (14), and impulse ratios extrapolated from sprint performance force data (impulse
ratio of ~20%, 6 and 8). This suggests that the impulse ratio of resistance exercises used to
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Kettlebell snatch mechanics
13
enhance sprint ability may be more important than initially thought, and that greater thought
should be given to plane specific resistance exercise selection (16). For example, it would
appear that the impulse ratio of 2-handed exercise might make a useful addition to a strength
and conditioning program designed to improve general sprint ability. Conversely, the impulse
ratio of kettlebell snatch exercise was about 30% less than typical sprint performance impulse
ratios, and about 40% less than the 2-handed swing exercise impulse ratio (ES = 2.15). This
suggests that kettlebell snatch exercise may provide a more vertical-plane specific training
effect.
With the exception of the differences that have already been discussed, the principle
difference between kettlebell snatch and 2-handed swing exercise appears to be that kettlebell
snatch exercise somewhat paradoxically represents a ballistic exercise that requires similar
mechanical output to 2-handed swing exercise. The 2-handed swing exercise is often thought
of as being a ballistic exercise. However, comparison of traditional ballistic and non-ballistic
resistance exercises indicates that the key difference is a period of active braking that ends
the propulsion phase of the exercise prematurely. Similar mechanisms, including forceful
contraction of the upper-back, trunk and upper-leg musculature, are employed toward the
latter stages of 2-handed swing exercise. This exerts control on the trajectory of the kettlebell,
stopping it from being displaced to potentially dangerous positions. Conversely, the kettlebell
snatch has a more obvious end point – locked arms overhead.
An obvious limitation to this study was that only one load, the load typically used to assess
competency at popular kettlebell certifications, was considered. Investigators recently
demonstrated that during 2-handed swing exercise impulse increased linearly with kettlebell
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Kettlebell snatch mechanics
14
mass from 16 kg to 32 kg (in 8 kg increments, (10)). Therefore, it is possible that kettlebell
snatch exercise with different loads could cause changes in mechanical output parameters,
like impulse, work and power, and suggests that study of kettlebell snatch exercise with a
range of loads could provide greater insight into the exercise. Furthermore, it should be
remembered that the kettlebell snatch exercise is a unilateral exercise, and as such it may
seem obvious that mechanical output from kettlebell snatch exercise would not exceed
mechanical output from 2-handed swing exercise. However, that the mechanical output of the
two exercises was largely comparable indicates that any attempt to equalize left and right side
training load would double the amount of mechanical work that must be performed.
Two other limitations warrant further consideration, and provide areas for future research.
First, these data were obtained from subjects who were relatively well trained in both the
kettlebell snatch and 2-handed swing exercise. Therefore, applying these results to subject
populations with differing kettlebell exercise experience may not be appropriate. However, it
should also be noted the recent research has shown 2-handed swing exercise with relatively
light loads (12-16 kg) by relatively untrained subjects (kettlebell exercise specifically and
resistance exercise in general) demonstrated significant improvements in maximum and
explosive strength after six weeks (11). The final limitation that should be considered is that
this study considered mechanical output data derived from ground reaction force. While these
data provide useful information about fundamental biomechanical parameters for strength
and conditioning practitioners, they are limited to describing the mechanical output of the
CM. Future research should consider accompanying motion analysis. This could provide
information about kettlebell and joint kinematics and kinetics, and might provide the
opportunity to compare mechanical output data from kettlebell and barbell snatch exercise
variations.
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Kettlebell snatch mechanics
15
PRACTICAL APPLICATIONS
The results of this study show that while a larger mechanical output was required to
horizontally displace the CM during 2-handed swing exercise, the mechanical outputs of the
two exercises were largely comparable. The bilateral nature of 2-handed swing exercise does
appear to afford greater control over the kettlebell. Further, research has already shown that
2-handed swing exercise improves maximum and explosive strength. However, the unilateral
and overhead nature of kettlebell snatch exercise could afford a greater trunk and shoulder
stability training effect, but would require more than twice the lower-body work to achieve
this. Therefore, the results of the present study suggest that kettlebell snatch and 2-handed
swing exercise could have a positive impact on a wide range of athletic applications, and that
strength and conditioning coaches should consider using kettlebell snatch and 2-handed
swing exercise interchangeably for the ballistic component of their athlete strength and
conditioning programs.
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12. Manocchia, P, Spierer, DK, Lufkin, AKS, Minichiello, JM, and Castro, J. Transference of
kettlebell training to strength, power and endurance. J Strength Cond Res 27: 477-484,
2013.
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Kettlebell snatch mechanics
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13. McGill, SM, and Marshall, LW. Kettlebell swing, snatch and bottoms-up carry: back and
hip muscle activation, motion and low-back loads. J Strength Cond Res 26: 16-27, 2012.
14. Morin, J-B, Edouard, P, and Samozino, P. Technical ability of force application as a
determinant factor of sprint performance. Med Sci Sports Exerc 43: 1680-1688, 2011.
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kettlebell training on vertical jump, strength, and body composition. J Strength Cond Res
26: 1199-1202, 2012.
16. Randell, AD, Cronin, JB, Keogh, JL, and Gill, ND. Transference of strength and power
adaptations to sports performance – horizontal and vertical force production. Strength
Cond J, 32: 100-106, 2012.
17. Tsatsouline, P. (2006). Enter the Kettlebell. St. Paul, MN: Dragon Door Publications, Inc.
18. Zebis, MK, Skott, J, Andersen, CH, Mortensen, P, Petersen, HH, Viskaer, TC, Jensen,
TL, Bencke, J, and Andersen, LL. Kettlebell swing targets semitendinosus and supine leg
curl targets biceps femoris: an EMG study with rehabilitation implications. Br J Sports
Med Epub ahead of print.
FIGURE HEADERS
Figure 1. Key positions of 2-handed swing exercise. The subject began with the kettlebell
held in 2 hands as if in a deadlift finish position; he hinged at the hip joint, driving the
ACCEPTED
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Kettlebell snatch mechanics
18
kettlebell back between his legs until the outside of just above his wrists made contact with
the inside upper thighs, at which point the motion was reversed, the object to project the
kettlebell forwards to approximately sternum height.
Figure 2. Key positions of kettlebell snatch exercise. The subject began with the kettlebell on
his locked-arm overhead, as seen in the final image. From here the kettlebell was lowered,
the elbow flexing slightly, and the hip joint hinged, driving the kettlebell back between his
legs until the outside of just above his wrists made contact with the inside and upper thighs
(the first image). From here the movement was reversed as portrayed by the image sequence.
Figure 3. Vertical and horizontal force-time (vertical force less system weight) curves from
representative kettlebell snatch performance (subject body mass = 93.3 kg). The beginning of
the braking phase, the end of the braking phase/beginning of the propulsion phase, and the
end of the propulsion phase are indicated with dotted lines. The period before the braking
phase began, and the after then propulsion phase ended is the lowering and lifting phase
momentum sub-phases, respectively.
Figure 4. Vertical and horizontal velocity-time curves from representative kettlebell snatch
performance (subject body mass = 93.3 kg). The beginning of the braking phase, the end of
the braking phase/beginning of the propulsion phase, and the end of the propulsion phase are
indicated with dotted lines. The period before the braking phase began, and the after then
propulsion phase ended is the lowering and lifting phase momentum sub-phases, respectively.
Figure 5. Vertical and horizontal displacement-time curves from representative kettlebell
snatch performance (subject body mass = 93.3 kg). The beginning of the braking phase, the
ACCEPTED
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Kettlebell snatch mechanics
19
end of the braking phase/beginning of the propulsion phase, and the end of the propulsion
phase are indicated with dotted lines. The period before the braking phase began, and the
after then propulsion phase ended is the lowering and lifting phase momentum sub-phases,
respectively.
Figure 6. Vertical and horizontal force-time (vertical force less system weight) curves from
representative 2-handed swing exercise performance (subject body mass = 93.3 kg). The
beginning of the braking phase, the end of the braking phase/beginning of the propulsion
phase, and the end of the propulsion phase are indicated with dotted lines. The period before
the braking phase began, and the after then propulsion phase ended is the lowering and lifting
phase momentum sub-phases, respectively.
Figure 7. Vertical and horizontal velocity-time curves from representative 2-handed swing
exercise performance (subject body mass = 93.3 kg). The beginning of the braking phase, the
end of the braking phase/beginning of the propulsion phase, and the end of the propulsion
phase are indicated with dotted lines. The period before the braking phase began, and the
after then propulsion phase ended is the lowering and lifting phase momentum sub-phases,
respectively.
Figure 8. Vertical and horizontal displacement-time curves from representative 2-handed
swing exercise performance (subject body mass = 93.3 kg). The beginning of the braking
phase, the end of the braking phase/beginning of the propulsion phase, and the end of the
propulsion phase are indicated with dotted lines. The period before the braking phase began,
and the after then propulsion phase ended is the lowering and lifting phase momentum sub-
phases, respectively.
ACCEPTED
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Kettlebell snatch mechanics
20
TABLE HEADERS
Table 1. Mean (SD) vertical and horizontal impulse and mean force magnitude and rate
(mean power) of work performed displacing the CM vertically and horizontally during
kettlebell snatch and 2-handed swing exercise.
Table 2. Mean (SD) work and power of displacing the CM vertically and horizontally during
kettlebell snatch and 2-handed swing exercise.
Table 3. Mean (SD) kettlebell snatch and 2-handed swing exercise braking and propulsion
phase durations (s).
Table 4. Mean (SD) vertical and horizontal displacement of the CM (m) during kettlebell
snatch and 2-handed swing exercise.
Table 5. Mean (SD) kettlebell snatch and 2-handed swing exercise impulse ratios.
ACCEPTED
Copyright � Lippincott Williams & Wilkins. All rights reserved.
Table 1. Mean (SD) vertical and horizontal impulse and mean force magnitude and rate (mean power) of work performed displacing the CM vertically and horizontally during kettlebell snatch and 2-handed swing exercise.
Impulse (N.s) Mean force (N)
Kettlebell snatch 2-handed swing Kettlebell snatch 2-handed swing
Vertical Horizontal Vertical Horizontal Vertical Horizontal Vertical Horizontal
Braking 103.34* 18.18 99.40* 26.11† 261.11* 43.66 362.43*‡ 88.39†
23.52 9.32 38.19 9.95 62.39 21.93 222.23 32.82
Propulsion 104.62* 17.50 101.84*‡ 32.22†‡ 271.89* 41.57 291.37* 86.71†
31.77 12.74 39.52 6.94 106.80 29.85 167.54 24.33 * = Vertical significantly greater than horizontal † = 2-handed swing value significantly greater than kettlebell snatch value ‡ = Propulsion phase value significantly different to Braking phase value
Table 2. Mean (SD) work and power of displacing the CM vertically and horizontally during kettlebell snatch and 2-handed swing exercise. Work (J) Mean power (W)
Kettlebell snatch 2-handed swing Kettlebell snatch 2-handed swing
Vertical Horizontal Vertical Horizontal Vertical Horizontal Vertical Horizontal
Braking 270.11* 1.72 233.08* 4.38† 676.25* 4.33 817.01*‡ 18.16†
83.73 1.21 90.54 2.13 201.82 3.05 427.71 8.54
Propulsion 253.55* 0.96 253.11* 4.79† 655.28* 4.15 705.49* 16.82†
71.18 2.05 88.44 2.22 231.41 4.28 375.52 8.18 * = Vertical significantly greater than horizontal † = 2-handed swing value significantly greater than kettlebell snatch value ‡ = Propulsion phase value significantly different to Braking phase value
ACCEPTED
Copyright � Lippincott Williams & Wilkins. All rights reserved.
Table 3. Mean (SD) kettlebell snatch and 2-handed swing exercise braking and propulsion phase durations (s). Kettlebell snatch 2-handed swing
0.40† 0.30 Braking 0.07 0.07
0.41 0.39‡ Propulsion
0.08 0.07 † = Kettlebell snatch value significantly longer than 2-handed swing exercise value ‡ = Propulsion phase value significantly longer to Braking phase value
Table 4. Mean (SD) vertical and horizontal displacement of the CM (m) during kettlebell snatch and 2-handed swing exercise. Kettlebell snatch 2-handed swing
0.22*† 0.18* Vertical 0.03 0.05
0.08 0.06 Horizontal
0.02 0.02 * = Vertical significantly greater than horizontal † = Kettlebell snatch value significantly greater than 2-handed swing value
Table 5. Mean (SD) kettlebell snatch and 2-handed swing exercise impulse ratios. Kettlebell snatch 2-handed swing
14% 21%† Braking 6% 7%
14% 26%† Propulsion
10% 7% † = 2-handed swing value significantly greater than kettlebell snatch value
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